Compass Pathways COMP360 Delivers on Phase 2 Results

Psilocybin drug meets safety standards, company announces key management changes.

Compass Pathways said May 8 that an open-label Phase 2 study of its investigational COMP360 psilocybin therapy met its primary safety objective and showed meaningful improvements in PTSD symptoms through 12 weeks of follow-up.

The study involved 22 patients with PTSD who received a single 25-milligram dose of COMP360, a synthetic form of the psychedelic compound found in psilocybin mushrooms.

According to Compass, COMP360 was well-tolerated with no serious adverse events reported. The most common side effects included headache, nausea, crying and fatigue.

In addition, patients exhibited clinically significant and durable reductions in PTSD symptom severity as measured by the Clinician-Administered PTSD Scale (CAPS-5). At week 12, there was a mean 29.5-point decrease from baseline in total CAPS-5 scores.

High response and remission rates relative to baseline were also observed. By week 4, 81.8% of patients achieved a response, defined as at least a 15-point CAPS-5 improvement, while 63.6% met the criteria for remission with scores below 20. These effects were largely sustained at week 12.

“These results, with early and lasting improvement in symptoms following a single administration of COMP360, are highly encouraging,” said Dr. Guy Goodwin, Chief Medical Officer of Compass Pathways. “These observations, even with a small, open-label study, suggest that COMP360 could provide a clinically meaningful benefit and substantially improve patient daily function and quality of life. The well tolerated safety profile for COMP360 in patients with PTSD, with no serious adverse events observed, advance our understanding of potential applications of COMP360. We look forward to submitting the full results of this study for publication and potential presentation at an upcoming medical conference.”

Meanwhile, Compass reported a net loss for the first quarter of $35.2 million compared with $24.2 million, or $0.57 loss per share, during the same period in 2023. The company also said Michael Gold will replace Trevor Mill as chief research and development officer.

Mill led the development of the COMP360 program in treatment-resistant depression and launched programs in PTSD and anorexia. He is leaving Compass to pursue other opportunities, the company said.

Gold previously served as chief medical officer at Neumora Therapeutics.